I just ran another quick test.

I was able to create another C# "ASP.NET AJAX-Enabled Web Application" project in a temporary directory. I imported all of the code from within the CuteEditor_for_NET6\Framework 2.0\cs directory. I created a new web site in IIS and pointed it at the new project that I created. When I pointed a browser at the new project website, each one of the samples that I clicked on ran perfectly.

I don't know what is going on with my original application, but this test ran successfully.

I'm going to import elements from my original application into this test project one by one and see when it breaks. Something I'm doing in my original application or some entry in my web.config must be conflicting.